Project description:The somatic missense point mutation c.402C>G (p.C134W) in the FOXL2 transcription factor is pathognomonic for adult-type granulosa cell tumours (AGCT) and a diagnostic marker for this tumour type. However, the molecular consequences of this mutation and its contribution to the mechanisms of AGCT pathogenesis remain unclear. To explore the mechanisms driving FOXL2C134W pathogenicity we engineered V5-FOXL2 and V5-FOXL2C134W doxycycline inducible isogenic cell lines and performed ChIP-seq and transcriptome profiling following transgenic induction. Interestingly we found that FOXL2C134W associates with the majority of FOXL2 binding sites as well as a large collection of novel regions throughout the genome. De novo motif analysis of the DNA elements uniquely bound by FOXL2C134W revealed a novel DNA motif that was not seen in the shared or FOXL2 specific DNA elements and we validated an altered DNA binding specificity for FOXL2C134W using in vitro band shift assays. Integrated analysis of FOXL2C134W specific proximal promoter binding sites and differential gene expression identified direct targets of FOXL2C134W. We validated one such target and demonstrated a FOXL2C134W dependent sensitivity to a therapeutic that targets survivin (YM155). Taken together our results suggest that FOXL2C134W pathogenicity in AGCT is driven in part by an alteration in DNA binding specificity contributing to an oncogenic transcriptional program.
Project description:It has previously been shown that FOXL2 and ESR1 cooperate to repress the testis-determining gene Sox9 in murine granulosa cells, and suggested that FOXL2/ESR1 cooperation may be central to granulosa cell differentiation (Uhlenhaut et al., 2009). However, no study has so far compared the DNA-binding of FOXL2 and ESR1 at the genomic level or analyzed the impact of FOXL2 on ESR1 binding to its regulatory elements. Here, we have analyzed and compared the genomic locations recognized by ESR1 and FOXL2 in E2-treated primary murine granulosa cells. Input DNA, FOXL2 and ESR1 ChIP
Project description:It has previously been shown that FOXL2 and ESR1 cooperate to repress the testis-determining gene Sox9 in murine granulosa cells, and suggested that FOXL2/ESR1 cooperation may be central to granulosa cell differentiation (Uhlenhaut et al., 2009). However, no study has so far compared the DNA-binding of FOXL2 and ESR1 at the genomic level or analyzed the impact of FOXL2 on ESR1 binding to its regulatory elements. Here, we have analyzed and compared the genomic locations recognized by ESR1 and FOXL2 in E2-treated primary murine granulosa cells.
Project description:The identity of the gonads is determined by which fate, ovarian granulosa cell or testicular Sertoli cell, the bipotential somatic cell precursors choose to follow. In most vertebrates, the fate of granulosa cells is controlled by a conserved regulator FOXL2. To understand how FOXL2 elicits its fate-determining action, we performed genome-wide analysis of FOXL2 chromatin occupancy in fetal ovaries. Combining genome-wide analysis of FOXL2 binding in the fetal ovary with transcriptomic analyses of Foxl2 gain-of-function and Foxl2 loss-of-function models, we identified potential pathways responsible for the feminizing action of FOXL2. Finally, comparison of FOXL2 genome-wide occupancy in the fetal ovary with testis-determining factor SOX9 genome-wide occupancy in the fetal testis revealed extensive overlaps, implying that antagonistic signals between FOXL2 and SOX9 occur at the chromatin level.
Project description:FOXL2 is a lineage determining transcription factor in the ovary, but its direct targets and modes of action are not fully characterized. Here, we explore the genomic targets of FOXL2. We found in particular that FOXL2 directly modulates Esr2 expression through a newly identified intronic element. Input DNA and FOXL2 ChIP
Project description:FOXL2 is a lineage determining transcription factor in the ovary, but its direct targets and modes of action are not fully characterized. Here, we explore the genomic targets of FOXL2. We found in particular that FOXL2 directly modulates Esr2 expression through a newly identified intronic element.
Project description:The Foxl2 transcription factor is required for ovarian function during follicular development. Our approach to begin to understand Foxl2 function is through the identification of Foxl2 regulated genes in the ovary. Transiently transfected KK1 mouse granulosa cells were used to identify genes that are potentially regulated by Foxl2. KK1 cells were transfected in three groups (mock, activated, and repressed) and twenty-four hours later RNA was isolated and submitted for Affymetrix microarray analysis. Experiment Overall Design: To increase the potential of Foxl2 to alter gene expression levels of putative target genes, two fusions were constructed consisting of Foxl2 fused to the activation domain of the Herpes simplex virus VP16 transcription factor (Foxl2-VP16) and Foxl2 fused to the repression domain of the murine MAD transcription factor (Foxl2-MAD). Levels of gene expression were compared between mock transfected cells and those that were transfected with Foxl2-VP16 and Foxl2-MAD, respectively.
Project description:FOXL2 is a transcription factor essential for female fertility, expressed in somatic cells of the ovary, notably granulosa cells. In the mouse, Foxl2 deletion leads to partial sex reversal postnatally. However, deletion of the gene in 8-week-old females leads to granulosa to Sertoli cell transdifferentiation. We hypothesised that different outcomes of Foxl2 deletion in embryonic versus adult ovary may depend on a different role played across ovarian development. Therefore, we characterised the dynamics of gene expression and chromatin accessibility changes in purified murine granulosa cells across key developmental stages (E14.5, 1 and 8 weeks). We then performed genome-wide identification of FOXL2 target genes and on-chromatin interacting partners by ChIP-SICAP. We found that FOXL2 regulates more genes at postnatal stages, through the interaction with factors regulating primordial follicle activation (PFA), such as NR5A2, and others regulating steroidogenesis including AR and ESR2. As a proof of principle experiment, we chose one FOXL2 interactor, Ubiquitin specific protease 7 (USP7) and showed that deletion of this gene in granulosa cells leads to a blockage of PFA, impaired ovary development and sterility. Our study constitutes a comprehensive resource for exploration of the molecular mechanisms of ovarian development and causes of female infertility.
Project description:Despite their distinct biology, granulosa cell tumours (GCTs) are treated the same as other ovarian tumours. Intriguingly, a recurring somatic mutation in the transcription factor Forkhead Box L2 (FOXL2) 402C>G has been found in nearly all GCTs examined. This investigation aims to identify the pathogenicity of mutant FOXL2 by studying its altered transcriptional targets. The expression of mutant FOXL2 was reduced in the GCT cell line KGN, and wildtype and mutant FOXL2 were overexpressed in the GCT cell line COV434. Comparisons were made between the transcriptomes of control cells and cells altered by FOXL2 knockdown and overexpression, to detect potential transcriptional targets of mutant FOXL2. Comparisons were made between the transcriptomes of control cells and cells altered by FOXL2 knockdown and overexpression, to detect potential transcriptional targets of mutant FOXL2.
Project description:Despite their distinct biology, granulosa cell tumours (GCTs) are treated the same as other ovarian tumours. Intriguingly, a recurring somatic mutation in the transcription factor Forkhead Box L2 (FOXL2) 402C>G has been found in nearly all GCTs examined. This investigation aims to identify the pathogenicity of mutant FOXL2 by studying its altered transcriptional targets. The expression of mutant FOXL2 was reduced in the GCT cell line KGN, and wildtype and mutant FOXL2 were overexpressed in the GCT cell line COV434. Comparisons were made between the transcriptomes of control cells and cells altered by FOXL2 knockdown and overexpression, to detect potential transcriptional targets of mutant FOXL2. Comparisons were made between the transcriptomes of control cells and cells altered by FOXL2 knockdown and overexpression, to detect potential transcriptional targets of mutant FOXL2. Mutant FOXL2 was silenced in KGN cells with the use of siRNA and a non-targetting siRNA control. Wildtype and mutant FOXL2 were overexpressed in COV434 cells with the use of overexpression plasmids and an empty plasmid control. Each experiment was performed in triplicate. Total RNA was harvested at 24h post transfection and hybridised to Affymetrix U133 plus 2.0 arrays.